Ongoing evolution of swine influenza viruses: a novel reassortant.

A novel H3N2 influenza virus strain isolated in Germany from pigs with clinical symptoms of influenza is described. It was characterised by neutralisation test, hemagglutination inhibition test and complete sequencing of the genome. The data demonstrate the emergence of a H3N2 reassortant with the human-like HAH3 gene of prevalent European porcine H3N2 influenza viruses and a NAN2 gene of the European porcine H1N2 viruses. The gene segments of the internal proteins are avian-like, consistent with European porcine influenza viruses. Analysis of GenBank sequence data reveals numerous reassortment events in recent years, demonstrating ongoing evolution of swine influenza viruses.